increase the size of r1a2 images - bezillabrowser fails to install

Description

installoptionalpackage -a bezillabrowser currently fails in haiku-r1a2-rc-hrev36601-x86gcc2hybrid-vmware due to full disk.
BeZillaBrowser needs 48 MB of free disk space to be downloaded and extracted, the current free space is 43 MB.

For comparison, the r1a1 vmware and raw images came with BeZillaBrowser preinstalled and weighed in at 600 MB (70 MB free). r1a2-rc-hrev36601 comes without BeZillaBrowser and is currently 650 MB (43 MB free).